#include<iostream>
#include<string>
using namespace std;
template<class t>
struct BStreenode
{
   typedef BStreenode<t> Node;
   Node *_left;
   Node *_right;
   t _Val;
   BStreenode(const t& key)
     :_left(nullptr)
      ,_right(nullptr)
      ,_Val(key)
   {}
};
int main()
{
   

  return 0;
}
